Define "conservation of mass"

The conservation of mass, also known as the principle of mass conservation, is a fundamental concept in physics and chemistry. It states that the total mass of an isolated system will remain constant, regardless of the processes acting inside the system. This principle implies that mass can neither be created nor destroyed, although it may be rearranged in space and changed into different types of particles. This principle is a direct consequence of the laws of physics, specifically, the law of conservation of energy.